Aside from making mysterious dodecahedrons, that is.
Article here.
(And no, it's not The Holy Hand Grenade of Antioch
)
Since 1739, some 130 of these objects [varying in size from about 2" to 4" like this one] have been discovered across Northern and Western Europe. While archaeologists have dated the relics to Roman times, they have been baffled by the objects for centuries, with no consensus ever emerging on what they were for. There is no known written description of them in ancient texts; nor do any pictorial references exist...
...Proponents of this theory [religious or ritual object] also point to the intricacy of the object itself, suggesting it probably had special value. According to Hitchens, the relic was made using a lost-wax bronze-casting process, an extremely technical feat — made even more challenging by the fact that the final product was hollow. “It’s a difficult shape to work with. You have to be really at the top of your game to make one of these,” she said...
Article here.
(And no, it's not The Holy Hand Grenade of Antioch

Since 1739, some 130 of these objects [varying in size from about 2" to 4" like this one] have been discovered across Northern and Western Europe. While archaeologists have dated the relics to Roman times, they have been baffled by the objects for centuries, with no consensus ever emerging on what they were for. There is no known written description of them in ancient texts; nor do any pictorial references exist...
...Proponents of this theory [religious or ritual object] also point to the intricacy of the object itself, suggesting it probably had special value. According to Hitchens, the relic was made using a lost-wax bronze-casting process, an extremely technical feat — made even more challenging by the fact that the final product was hollow. “It’s a difficult shape to work with. You have to be really at the top of your game to make one of these,” she said...